What is the G.C.F of 28 and 100?

Answer 1

By Euclid's algorithm, that's the same as the gcf of 28 and 16 - where 16 is calculated as the remainder of 100 divided by 28. (You can continue by doing the division of 28 by 16; the next pair will be 16 and that remainder.)

Answer 2

The greatest common factor of 28 and 100 is 4.

Answer 3

28 = 2 x 2 x 7
100 = 2 x 2 x 5 x 5
The factors they have in common are 2 x 2, so the greatest common factor is 4.

Answer 4

You have :

28 = ( 2 ) ( 2 ) ( 7 )

100 = ( 2 ) ( 2 ) ( 5 ) ( 5 )

The greatest common factor is ( 2 ) ( 2 ) or 4 <--------------